Device and method for buffering a plurality of goods or groups of goods and paper handling system comprising same

ABSTRACT

A device for buffering a plurality of goods or groups of goods includes a buffer section configured to receive a plurality of goods or groups of goods. In addition, a buffer transport is provided, configured to move a good or group of goods at a buffer transport speed. A runout is configured to move out a good or group of goods from the device at a runout speed which is higher than the buffer transport speed. The runout is additionally configured to take over transport of a good or group of goods before the good or group of goods has reached an end of the buffer section.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of copending InternationalApplication No. PCT/EP2011/068354, filed Oct. 20, 2011, which isincorporated herein by reference in its entirety, and additionallyclaims priority from German Application No. 10 2010 043 063.3, filedOct. 28, 2010, which is also incorporated herein by reference in itsentirety.

BACKGROUND OF THE INVENTION

Embodiments of the invention relate to processing goods or groups ofgoods, in particular to processing sheets which are processed within apaper handling system as individual sheets or groups of sheets.

Paper handling systems exemplarily serve for producing letters beingsent to a plurality of recipients, using which telephone bills, bankstatements or similar things are, for example, sent. Cover notes of thiskind either include an individual sheet or a plurality of sheets whichare then processed within the system as a group. The sheets processed bythe system are then exemplarily introduced into an envelope by means ofan inserter and sent to a recipient. In such paper handling systems, thesheets forming the plurality of cover letters are fed via one or severalinput channels, collecting the sheets of a group of sheets beingnecessitated before processing same together. The sheets may exemplarilybe provided by a paper roll onto which the plurality of sheets have beenprinted before, exemplarily in a multi-up manner. The roll is then fedvia the input channel and at first cut in a longitudinal and atransverse direction so as to generate individual sheets which aresubsequently collected in a collection stage as individual sheets orgroups of sheets. The speed at which the sheets of a collecting stagecan be provided may differ depending on the speed at which same aremoved out of the collection stage for being provided to subsequentprocessing, such as, for example, a folding mechanism.

FIG. 1 shows a paper handling system including a plurality of handlingstages, i.e. a cutter 100, a so-called merger 102, a collecting stage104 and a folding mechanism 106, schematically. At an input, the cutter100 receives a paper web 108 which is imprinted with the text of theindividual sheets 110 and 112 to be generated later on in a several-upmanner. In the upper section, FIG. 1 shows a schematic top viewillustration of the processed sheets and, in the lower part, a schematicside view illustration of the sheets. The cutter 100 causes alongitudinal cut and a transverse cut of the paper web 108 so as toseparate the individual sheets 110 and 112, such that, as is shown inFIG. 1, after cutting, there are single sheets. From the cutter 100, theindividual sheets 110 and 112 are transferred in parallel to the merger102, or merging web, which moves both sheets 110 and 112 such that theyare arranged one above the other, as is shown in FIG. 1. The sheetsarranged in this way are transferred from the merger 102 to thecollecting stage 104. As has been mentioned, the folding mechanism 106follows the collecting stage 104. In order to decouple the speed atwhich the sheets are received from the collecting stage 104 from thespeed at which the folding mechanism 106 can process sheets, a buffer114 (illustrated by a buffer section 114) is arranged between the outputof the collecting stage 104 and the input of the folding mechanism 106,a plurality of individual sheets or groups of sheets 116 a to 116I beingarranged in the buffer, for example in a shingled arrangement, as isshown in FIG. 1. The collecting stage 104 is configured to deposit thereceived sheets 110, 112 at a first buffer stage along the buffersection 114 of the buffer. At the end of the buffer section 114, thegroup of sheets, or individual sheet 1161, present at the last bufferposition is withdrawn at a speed corresponding to a processing speed ofthe following component, in this case the folding mechanism. The groupof sheets 118 withdrawn is fed to the folding mechanism, exemplarily adouble folding mechanism, and the folded groups 118′ are fed to furtherprocessing. Further processing may either be sealing, for example, theshort sides of the folded group of sheets 118′ such that the mail pieceto be sent is finished here already. In this case, at least one of theindividual sheets 110, 112 is printed such that an addressee is visibleon the outside after the folding process. Alternatively, the foldedgroup of sheets 118′ may be fed to an inserter which subsequentlyinserts the group of sheets 118′ into envelopes.

Providing the buffer section 114 allows decoupling the processing speedsof the components arranged in front of the collection stage 104 from theprocessing speed of the components arranged after the collecting stage104. This means that the input channel formed by the cutter and themerger 102 may operate at a basically constant speed, since the speedexcess relative to the processing speed of the folding mechanism 106 iscompensated by the buffer section 114. Conventional buffer sections 114operate such that an individual sheet or group of sheets is deposited atthe first buffer stage 116 a and passes each individual buffer stage 116a-116I in correspondence with the speed of a buffer transport provided,irrespective of the filling state of the buffer section 114. When thegroup reaches the output of the buffer section 114, it is withdrawn.

The arrangement of a buffer is not limited to the configuration of apaper handling system as shown in FIG. 1. Basically, such a buffer isemployed wherever decoupling of speeds is necessitated, such as, forexample, where a preceding component provides a good or a group of goodsat a speed which may be higher than a speed at which a subsequentcomponent is able to accept the good or group of goods. FIG. 1 a showsfurther examples of the arrangement of one or several buffers in a paperhandling system, wherein a buffer may be arranged at all positions oronly at selected positions shown in FIG. 1 a. A buffer 114 may generallybe arranged between the input channel and an inserter 120. In the inputchannel of the paper handling system, a buffer 114 may be arrangedbetween the merger 102 and the collecting stage 104 (not shown in FIG. 1a) and/or between the collecting stage 104 and the folding mechanism 106and/or between the folding mechanism 106 and a merging web 122 and/orbetween the merging web 122 and the inserter 120. In addition, a buffer114 may be arranged between the inserter 120 and a post-processingcomponent, such as, for example, a postage module 124.

Different approaches for realizing a buffer within a paper handlingsystem are known from conventional technology. EP 1 206 402 A and EP 1206 407 A describe buffers which receive a plurality of sheets or groupsof sheets in a shingled manner, and, in particular, approaches foraccepting sheets or groups of sheets into such a buffer stage in ashingled manner, or withdrawing sheets of a group from such a bufferstage. EP 1 433 733 A describes a buffer transport system for aninserting system in which each buffer stage is formed by several pairsof rolls including associated sensorics so as to optionally provide afour-stage or six-stage buffer, depending on the format to be processed.EP 1 108 668 A describes a temporary storage for documents whereincontinuous transport is provided for by belts by means of whichdocuments taken over from a preceding component are moved through thebuffer. A movable slide is provided for establishing a buffer sectionwithin the system. WO 2004/063071 A describes a buffer for receiving astack of sheets wherein the sheets are deposited in a shingled mannerand the entire stack is moved to the output for withdrawing a sheet soas to be able to withdraw a lower sheet from the stack.

EP 1 433 733 A relates to a flexible buffer transport system forbuffering collected documents, the buffer being formed by a plurality ofrolls and sensors which may each be controlled individually by specialmotors. Depending on the format to be processed, buffer positions areestablished using the controller and corresponding rolls are associatedto the individual buffer positions and driven together. In a case inwhich there are no downstream documents within the buffer transport fora collected group, transfer of the collected documents to the transportof the following inserter takes place synchronously and depending on theavailability of the transport of the following envelope. When there areone or several empty buffer positions in the direction towards theoutput, the buffer section in accordance with EP 1 433 733 A avoidspassing all the buffer stages in correspondence with the buffertransport speed by moving on at the speed of the following component,however, the setup and control in accordance with EP 1 433 733 A arecomplicated with regard to both mechanics and controlling. In addition,this known buffer section does not allow a shingled arrangement of goodsor groups of goods.

SUMMARY

Departing from this known technology, it is the object of the presentinvention to develop a buffer such that moving the group of goods orgood out quickly is made possible such that unnecessary queue times, asmay be found in the known technology in accordance with FIG. 1, areavoided without complicating the setup in terms of mechanics andcontrolling.

According to an embodiment, a device for buffering a plurality ofindividual sheets or groups of sheets may have: a buffer sectionconfigured to receive a plurality of individual sheets or groups ofsheets; a buffer transport configured to move an individual sheet orgroup of sheets at a buffer transport speed; and a runout configured tomove out an individual sheet or group of sheets from the device at arunout speed which is higher than the buffer transport speed;characterized in that the runout is configured to act on an individualsheet or group of sheets at a last occupied position along the buffersection so as to take over transport of the individual sheet or thegroup of sheets before the individual sheet or group of sheets hasreached an end of the buffer section.

According to another embodiment, a paper handling system may have: oneor several handling stages; and at least one device as mentioned abovefor collecting individual sheets or groups of sheets.

According to still another embodiment, a method for buffering aplurality of individual sheet or groups of sheets in a buffer sectionfor receiving a plurality of individual sheet or groups of sheets, abuffer transport moving an individual sheet or group of sheets at abuffer transport speed, and a runout moving out an individual sheet orgroup of sheets at a runout speed which is higher than the buffertransport speed, may be characterized by the following step: acting, bythe runout for moving out, on an individual sheet or group of sheets ata last occupied position along the buffer section so as to take overtransport of the individual sheet or the group of sheets before theindividual sheet or group of sheets has reached an end of the buffersection.

In accordance with embodiments of the invention, the buffer sectionincludes a plurality of successive buffer positions, each bufferposition being configured to receive a good or group of goods. Thebuffer positions along the buffer section are set fixedly or aresettable variably in dependence on a dimension (such as, for example,length) of the good to be buffered or group of goods to be buffered.

In accordance with embodiments of the invention, a novel buffer deviceis suggested, in which, unlike in conventional buffers, a good or groupof goods does no longer have to pass all the buffer positions in abuffer in correspondence with a buffer transport speed until finallywithdrawal for further transport to a following component is achieved.In accordance with embodiments of the invention, this is achieved by thefact that each buffer position within the buffer device may still beoccupied by a good or group of goods, however, in case that bufferpositions remain unoccupied before the runout, a kind of “moveable”runout is provided which allows withdrawal of a good or group of goodsfrom the last occupied buffer position without the good or group ofgoods having to pass each individual following empty buffer stage incorrespondence with the clocked driving of the buffer transport.Exemplarily, when forming groups, the runout is moved to the lastoccupied buffer position to cause direct withdrawal for subsequentprocessing there, wherein this last buffer position is closer to theoutput of the buffer device with several successive small groups andcloser to the input of the buffer device with several successive largergroups. However, a situation in which every subsequent buffer positionis passed using the buffer transport is avoided, rather a finishedcollected group is withdrawn directly from the last occupied bufferposition for subsequent processing. In accordance with embodiments ofthe invention, this is realized by a movable runout which is moved tothe last occupied buffer position so as to accept a good or group ofgoods there. Alternatively, providing selectively connectable runoutelements of the runout at predetermined discrete points may be provided,exemplarily a runout element may be provided at each buffer positionsuch that, in case a central buffer position is the last occupied bufferposition, the runout element associated to this buffer position and alsoall other runout elements associated to the subsequent empty bufferpositions are lowered so as to allow contact to the good to be moved outso as to allow accelerated move out, irrespective of the buffertransport of the buffer device.

The known technology mentioned above in accordance with EP 1 433 733 Ais based on an approach in which the concept of separating buffertransport and runout transport is abandoned and instead a plurality ofindividually driven pairs of rolls are used which allow thefunctionality of the buffer transport on the one hand and thefunctionality of the runout transport on the other hand by correspondingcontrolling. In accordance with embodiments of the invention, incontrast, the basic concept of a buffer as has been described referringto FIG. 1 is maintained, i.e. a concept which provides for providingbuffer transport and runout transport, wherein the buffer transportmoves the good from one buffer stage to the next within the buffer andthe runout transport passes the good on to a subsequent component. Theapproach in accordance with embodiments of the invention providesmodification of this conventional buffer approach in that the runoutwhich so far has been arranged statically at the end of the buffersection is configured to be “moveable” and thus goods are moved out froma last occupied buffer position.

In contrast to conventional approaches, the device in accordance withembodiments of the invention is of advantage finished collectedgoods/groups of goods may now be moved out rapidly since it is no longernecessary to pass the entire buffer section from one buffer position tothe next in accordance with the buffer transport speed. In contrast toknown technology, as is known from EP 1 433 733 A, the approach inaccordance with an embodiment of the invention is of advantage since thefunctionality of the buffer device and corresponding elements, i.e.in-feed, buffer section and runout, is maintained in principle, whereasin accordance with the document cited a complete modification of theconventional buffer device is necessitated. In accordance withembodiments of the invention, the control complexity is smaller sincethe basic controlling of the buffer section essentially remainsunchanged and only corresponding control of the moveable runout isnecessitated in order to cause early withdrawal of a group or individualgood from a last occupied buffer position along the buffer section. Incontrast to known technology, as is known from EP 1 433 733 A, theapproach in accordance with embodiments of the invention is of furtheradvantage since the goods or groups of goods may be accepted in thebuffer section in a shingled or non-shingled manner.

In accordance with embodiments of the invention, the buffer may be partof a collection stage which will then be able to collect and buffer atthe same time a plurality of goods or groups of goods.

In accordance with further embodiments of the invention, the buffertransport includes a first vacuum transport comprising a plurality ofvacuum chambers which may be activated selectively, and the runoutincludes a second vacuum transport comprising a plurality of vacuumchambers which may be activated selectively, wherein one or several ofthe activated vacuum chambers of the first vacuum transport may beprovided so as to define a position for receiving the good or group ofgoods. The first and second vacuum transports may be arranged next toeach other or above each other.

BRIEF DESCRIPTION OF THE DRAWINGS

Embodiments of the invention will be detailed subsequently referring tothe appended drawings, in which:

FIG. 1 is a schematic illustration of a paper handling system includinga plurality of handling stages, including a conventional buffer section;

FIG. 1 a shows further examples of the arrangement of one or severalbuffers in a paper handling system;

FIG. 2 is a schematic illustration of a buffer stage in accordance withan embodiment of the invention comprising a plurality of actuatablerunout modules along the buffer section;

FIG. 3 is a schematic illustration of the buffer stage of FIG. 2 inaccordance with another embodiment of the invention;

FIG. 4 is a schematic illustration of the buffer stage of FIG. 2 inaccordance with still another embodiment of the invention;

FIG. 5 is a schematic illustration of a buffer stage in accordance withan embodiment of the invention comprising a runout module moveable alongthe buffer section;

FIG. 6 is a side sectional illustration of the moveable runout inaccordance with FIG. 5 in accordance with an embodiment of theinvention;

FIG. 7 is a top view sectional illustration of the runout of FIG. 6along the line b-b in FIG. 6;

FIG. 8 shows an embodiment of an in-feed mechanism in accordance withembodiments of the invention;

FIG. 9 shows a guiding rail pair of the in-feed mechanism of FIG. 8 inaccordance with an embodiment; and

FIG. 10 is a schematic illustration of a buffer stage in accordance withanother embodiment of the invention.

DETAILED DESCRIPTION OF THE INVENTION

Same elements or elements having the same effect are provided with thesame reference numerals in the following description of embodiments ofthe invention.

An embodiment of the invention will be discussed below referring to FIG.2, wherein the runout is formed by a plurality of runout modules. FIG. 2shows a schematic illustration of the buffer stage 200 comprising anin-feed 202 for feeding the sheets to a buffer section 204 including aplurality of transport units 206 a-206 f, the transport units 206 a-206f being arranged at corresponding buffer positions 207 a-207 f of thebuffer 200 and being moveable between same. Each of the transport units206 a-206 f includes a clamping element 208, such as, for example, oneor several pairs of pliers 208 of which only the pair of pliers 208arranged at the transport unit 206 a is shown in FIG. 2. The pliers 208serve for clamping a good arranged at a transport unit 206, such as, forexample, an individual sheet or a group of sheets, such that same may bemoved through the buffer. The transport units 206 a-206 f are, forexample, arranged along a buffer transport 209, such as, for example,along a conveyer belt or along a conveyer chain, spaced apart from oneanother, wherein the conveyer chain is driven by a drive not shown inFIG. 2 in a clocked manner (in start/stop operation) so as to move thetransport units through the buffer section 204 in correspondence with apredetermined buffer transport speed, such that exemplarily the firsttransport unit 206 a shown in FIG. 2 has passed buffer positions 206 a-eafter five clocks and reached buffer position 206 f where the bufferposition 206 f is arranged in FIG. 2. In the example shown in FIG. 2,for reasons of simplicity, only an individual sheet 210 which isreceived by the first transport unit 206 a arranged at the first bufferposition 207 a is arranged in the buffer section 204. More precisely,the, in the direction of transport, back end of the sheet 210 is held atthe first transport unit 206 a by the clamp 208. The remaining bufferpositions along the buffer section 204 are unoccupied. If sheets werearranged here, too, a plurality of groups of sheets or individual sheetswould be arranged within the buffer section 204 in a shingled manner,similarly to what is shown in FIG. 1.

Additionally, the buffer stage 200 includes a runout 212 which in theembodiment shown is formed by a plurality of runout modules 212 a-e.Each of the runout modules 212 a-212 e includes a carrier 214 a-214 eprovided so as to carry a conveyer element 216 a-216 e. The conveyerelement 216 a-216 e may be formed by a roll, two or several rollsarranged one after the other in the direction of transport of the goodor group of goods, a belt or a roll of a D-shaped cross-section. In theembodiment shown in FIG. 2, the runout modules 212 a-212 e are arrangedso as to be moveable vertically, as is shown by corresponding arrows 213in FIG. 2. Each of the runout modules 212 a-212 e is associated to oneof the buffer positions 207 b-207 f downstream of the in-feed 202. Thefirst buffer position 207 a which is opposite the in-feed 202 has norunout module associated therewith. The clocked mode of driving thebuffer section 204 is such that, during a movement clock, a transportunit (such as, for example, 206 b) is advanced by a section from abuffer position (such as, for example, 207 b) to the next bufferposition (such as, for example, 207 c) such that a runout module will be“opposite” a transport unit.

The runout modules 212 a-212 e may be controlled individually so as tobe moved vertically between a first position and a second position. Inthe first position, the runout module 212 is arranged such that theassociated conveyer element 216 a does not engage the individual sheetor group of sheets arranged within the buffer, as is exemplarily shownin FIG. 2 using the runout modules 212 a-212 c which are arranged intheir first positions. In the second position, the runout modules, see,for example, runout modules 212 d and 212 e, are arranged such thattheir conveyer elements 216 engage a good to be transported so as toallow transport of the good irrespective of the transport speed of thebuffer transport 209.

As has been mentioned, in the embodiment illustrated in FIG. 2 only asingle sheet 210 is exemplarily arranged along the buffer section 204.Groups of sheets, folded goods or goods inserted in envelopes may alsobe buffered instead of an individual sheet. Same has been deposited atthe first buffer position 207 a by the in-feed 202 and received by thetransport unit 206 a present there at that time and held for transportalong the buffer section. Thus, the following buffer positions 206 b-206e are free or unoccupied. In accordance with conventional approaches,the transport unit 206 a would have to be moved along the buffer section204 in a clocked manner by means of the buffer transport until an, inthe direction of transport, front end of the sheet 210 has reached astationary runout arranged at the end of the buffer section where it isaccepted by same and removed. When exemplarily assuming that theposition of the stationary runout corresponded to the position of therunout module 212 e, in the embodiment of FIG. 2, at least one clockwould be necessitated for moving the sheet 210 on, only then couldremoval take place. In accordance with embodiments of the invention,however, early removal is allowed by finding out that the bufferpositions 207 b-207 f are unoccupied such that a runout module 214 dassociated to the front end of the sheet 210 and a following runoutmodule 212 e are lowered to the second position so as to allowengagement of the sheet 250. This causes removal of the individual sheet210 in the direction of the output of the buffer section by the runoutmodule 212 d in cooperation with the runout module 214 e at a speedindependent of buffer transport such that the sheet 210 is able to leavethe buffer section 204 early without at first having to wait until ithas reached the runout by means of the buffer transport.

In the embodiment illustrated in FIG. 2, the buffer additionallyincludes a sensor circuit configured to detect a position of a good orgroup of goods along the buffer section 204. The sensor circuit includesa plurality of sensors S which are illustrated schematically in FIG. 2,at least one sensor S each being associated to one of the bufferpositions 207 a-f so as to determine whether a buffer position isoccupied or unoccupied. The runout 212 is configured to determine, basedon the sensor signals, the buffer position along the buffer section 204where the transport of a good or group of goods is to be taken over bythe runout 212 in the manner described before. Alternatively, a positionof a good or group of goods in the buffer may be calculated withoutrequiring sensors which detect a position of the good along the buffersection. Calculation may then take place based on a speed at which thedrives of the buffer operate or at which the good or group of goods ismoved and based on a known format size of a good or the largest good ina group which may, for example, be provided by the job description. Thespeed of the drives or speed of the good or group of goods mayexemplarily be detected by suitable sensors.

It is to be pointed out here that, using FIG. 2, an embodiment has beendescribed in which the sheets or groups of sheets are arranged withinthe buffer section 204 in a shingled manner and are held by thetransport unit at a, in the direction of transport, back end. In thiscase, the sheets or groups of sheets are “pushed” along the buffersection. Alternatively, the sheets or groups of sheets may also be heldby the transport unit in a, in the direction of transport, front end. Inthis case, the sheets or groups of sheets are “pulled” along the buffersection. However, the invention is not limited to buffers which receivethe goods or groups of goods to be buffered in a shingled manner. Also,a non-shingled arrangement may be provided for such that, for example,one compartment each for receiving a sheet or group of sheets is formedby two transport elements arranged on the buffer transport in aspaced-apart manner. The spacing of the transport elements exemplarilycorresponds to a format length of the sheets to be processed. Dependingon the circumstances, a corresponding arrangement of the sheets in ashingled manner or non-shingled manner may be desirable.

The buffer transport 209 may be the pliers transport shown in FIG. 2.Other transport mechanisms may also be used, such as, for example, astud transport which includes individual compartments for receiving thegood or group of goods. The pliers or studs of the buffer transport 209are in fixed distances to one another, corresponding to the distance ofthe buffer positions 207.

As can be seen from FIG. 2, the original approach of separating runoutand buffer transports is maintained by the buffer transport 209 and therunout 212 each including separate transport elements. The buffertransport 209 may include pliers transport or stud transport and therunout 212 may include roll or belt transport.

Another embodiment of the invention wherein the runout 212 includes aplurality of runout modules, similarly to FIG. 2, is shown referring toFIG. 3. In the embodiment shown in FIG. 3, the runout modules 212 a-212e which are opposite the corresponding buffer positions 207 a-207 f orassociated thereto, are provided again. Additionally, for bridging thedistance between two successive buffer positions, further runout modules218 a-218 e which are equal in setup to the modules 212 a-212 e and arealso moveable in correspondence therewith between the first and secondpositions are provided. Each of the runout modules shown in FIG. 3includes a carrier which in the module 212 a is exemplarily referencedby the reference numeral 214 a. The carrier 214 a carries the conveyerelement 216 a which is mounted to be rotatable around an axis 224 a soas to allow rotation in the direction of the transport direction. Theadditional runout modules 218 a-218 e also include carriers 220 e andconveyer elements 222 e which are mounted to be rotatable around an axis226 e. In the runout modules in accordance with FIG. 3, the axes 224 and226 are moveable vertically, as is illustrated by the arrow 227 so as tocause lowering of the conveyer elements 216 and 222, respectively, fromthe first position in which there is no engagement of the goods, to thesecond position, where engagement of the goods is possible.

In the example shown in FIG. 3, the buffer section 204 contains threesheets or groups of sheets 210, 210′ and 210″, wherein the group 210 is,for example, held by the transport unit 206 c and the group 210′ by thetransport unit 206 b. Group 210″ is about to be introduced into thebuffer section and is to be received and held by the transport unit 206a. Similarly to FIG. 2, in FIG. 3, too, it is to be recognized thatthere are no further groups arranged in the direction of transport aftergroup 210 such that group 210 is moved out already before reaching theend of the buffer section 214 in correspondence with the teachings inaccordance with embodiments of the invention by moving the runoutmodules 212 d and 212 e and the runout modules 218 c-218 e from thefirst position to the second position so as to ensure engagement of thegood between the last occupied buffer position and the runout or outputof the buffer section. The conveyer elements of the runout modulesmentioned are driven at the necessitated removal speed which is higherthan the transport speed of the buffer section such that the group ofsheets 210 or individual sheet 210 is moved out rapidly.

FIG. 4 shows another embodiment which is similar to the embodiment inaccordance with FIG. 3. In the embodiment shown in FIG. 4, the runoutmodules are implemented such that no vertical movement thereof isnecessary between the first position and the second position. Rather,the conveyer elements 216 and 222 of the corresponding runout modulesare implemented by rolls having a D-shaped cross-section, so-calledD-rolls which are arranged in the module 212 a to be rotatable aroundthe corresponding rotational axis 224 and 226, respectively, in thedirection of the arrow 229 shown in FIG. 4. The conveyer elements 216,222 at the beginning are in a rest position, as is exemplarily shown inthe module 212 a where there is no engagement of the goods. For causingtransport of the goods, the conveyer element is rotated, as is shown inthe runout module 212 d so as to move same to a second position orthrough a second position so as to cause engagement of the sheet 210 tocause same to be conveyed. The runout modules following the module 212 dare driven in a staggered manner so as to cause temporally adjustedactuation of the corresponding conveyer elements 222 and 216 to causethe sheet 210 conveyed by the module 212 d to be conveyed further in thedirection of the output.

Another embodiment of the invention will be described below referred toFIG. 5. In FIG. 5, buffer 200 is shown again, wherein, unlike in theembodiment shown in FIGS. 2-4, the runout 212 is realized by a singlerunout module 230 which is movable along the direction of transport, asis illustrated in FIG. 5 by the arrow 231. The setup of the inlet andthe buffer section corresponds to the setup in accordance with FIG. 2and, similarly to FIG. 2, only an individual sheet 210 or group which isarranged along the buffer section 204 is illustrated for reasons ofsimplicity. Similarly to FIG. 2, in FIG. 5, too, the buffer is emptyafter sheet 210 such that it would be necessitated for reaching a fixedrunout at the end of the buffer section to move the sheet 210 throughthe buffer positions 206 b to 207 f in a clocked manner incorrespondence with the transport speed of the buffer transport untilthe, in the direction of transport, front end of the sheet 210 hasreached the stationary runout. Similarly to FIGS. 2 to 4, this isavoided in the embodiment shown in FIG. 5 by allowing early withdrawalof the sheet 210 when there are no further sheets, in the direction oftransport in front of the sheet, in the buffer section. In theembodiment shown in FIG. 5, the runout 212 includes the moveable module230 which includes a carrier 232 and a conveyer element 234 mounted tothe carrier 232 which may be implemented in the same manner as in themodules described before using FIGS. 2 and 3. The moveable module 230 isarranged such that its conveyer element 234 will be able, in everyposition, to engage a sheet or group of sheets 210, if there are anyalong the buffer section. When recognizing that sheet 210 is the lastsheet, the movable module 230 is moved, departing from a rest position,which is exemplarily arranged at the end of the buffer section, in thedirection of the buffer input until the front end of the sheet 210 whichin the example shown in FIG. 5 is at the buffer position 207 e has beenreached, wherein subsequently the sheet 210 is removed at a removalspeed which is higher than a transport speed of the buffer transport.For removal, it may be provided for that the module 230 moves in thedirection of the output during conveyance of the sheet by the conveyerelement 234 so as to ensure continuous conveying of the sheet.

An embodiment of the invention for realizing the moveable runout 212 inaccordance with

FIG. 5 will be discussed in greater detail below referring to FIGS. 6and 7. FIG. 6 shows a side sectional illustration of the runout and FIG.7 shows a top view sectional illustration. In FIG. 6, the buffer section204 is shown comprising the buffer positions 207 a to 207 k where thetransport units 206 a-206 k which are moved between the buffer positionsin a clocked manner in the conventional manner using a buffer transportare arranged. Exemplarily, the buffer transport 209 includes a chaincirculating around two rolls such that the transport units are movedback to the beginning of the buffer section when reaching the end of thebuffer section. In the embodiment shown in FIG. 6, sheets or groups ofsheets 210, 210′ and 210″ are shown in the buffer section, the group ofsheets 210 being held by the transport unit 206 b at the buffer position207 b and the group of sheets 210′ being held by the transport unit 206a at the buffer position 207 a, as can be recognized by the clampingmechanism 208 folded back. The group of sheets 210 is held either byanother buffer position not shown in FIG. 6 or has already beenintroduced so as to be received by a transport unit engaging the groupof sheets 210′ in the next clock.

The runout 212 includes a top belt transport 236 and a bottom belttransport 238. The top belt transport 236 includes a first return roll240 and a second return roll 242 for guiding a top transport belt 244.The top belt transport additionally includes the moveable runout module230 which is arranged to be moveable along the direction of transport ofthe goods 210, as is illustrated by the arrow 231. The sled 230 includesa carrier structure 232 where the conveyer element 234 is arranged so asto allow rotational movement. In addition, the carrier structure 232carries two return rolls 246 and 248 which are arranged one behind theother in a spaced-apart manner in the direction of transport. Thetransport belt of the top belt transport 236 is received by the returnrolls such that the first return roll 246 receives the belt 244 at aposition spaced apart from the buffer transport 204. The belt 244extends between the two return rolls 246 and 248 such that the secondreturn roll 248 guides the belt at a lower portion neighboring to thebuffer section 204. The first roll 240 of the top belt transport 236 hasgreater a diameter than the second roll 242 such that the belt is guidedbetween the second return roll 248 and the first roll 240 of the belttransport 236 neighboring to the buffer transport 240 such that the beltengages a good or group of goods as is shown in FIG. 6 at the referencenumeral 250 so as to cause removal thereof at a removal speed which ishigher than the buffer transport speed. The transport belt 244 is, in aportion between the second roll 242 of the belt transport 236 and thefront return roll 246 of the sled 230, guided in a manner spaced apartfrom the buffer section 204 such that same does not engage one orseveral goods arranged on the buffer section.

The conveyer element 234 is a roll element having a D-shapedcross-section (D roll) which is actuated when reaching a desiredwithdrawal position of the sled so as to catch a sheet at the position,exemplarily sheet 210 at the position 206 j, or the, in the direction oftransport, front edge thereof and introduce same by a rotation betweenthe belt 240 of the top belt transport and a belt 252 of the bottom belttransport 238 so as to allow removal at the withdrawal speed. The bottombelt transport also includes two rolls 254 and 256 over which the bottombelt 252 is guided. By the cooperation of the two belts 252 and 244 inthe portion behind the sled 230 in the direction of transport,withdrawal of the sheets or groups of sheets introduced in this regionis allowed at the desired removal speed.

Depending on which of the positions 207 shown in FIG. 6 is the lastoccupied position, i.e. the last position where there is a good, thesled 230 is moved to a suitable withdrawal position, exemplarily to aposition corresponding to the front end of the sheet held by a transportunit. When reaching the withdrawal position, the conveyer element 234 isactuated so as to move between the belts 244 and 252 and remove theobject at the removal position, exemplarily the sheet or group ofsheets.

FIG. 7 shows a top view illustration of the arrangement of FIG. 6 cut ina direction perpendicular to the plane of the sheet along the line b-b.In FIG. 7, the belt 244 redirected by the second return roll 248 can bemade out, as are the return rolls 240 and 242 of the top belt transport236. Additionally, it can be recognized that the sled 230 comprises acarry bar 258 arranged transverse to the direction of movement where twoconveyer elements 234 a and 234 b are arranged movably so as to causetransfer of a good to be removed in the region between the belts 244 and252 in the manner described above. Additionally, guide elements 260 aand 260 b which engage corresponding guiding rails 262 a and 262 b areprovided at the carry bar 258 so as to allow moving the sled back andforth along the direction of transport between the desired withdrawalpositions. The guiding rails 262 a and 262 b are exemplarily mounted tothe casing 264 of the arrangement, which is shown in FIGS. 6 and 7.Elements 266 a and 266 b are stops which are arranged at the guidingrails 262 a and 262 b so as to limit movement of the sled 230. Inaddition, in FIG. 7, the sheets or groups of sheets 210, 210′, 210″ areillustrated deposited in a shingled manner. Additionally, group 250 tobe moved out at the moment is shown.

An embodiment in which the runout transport includes the withdrawal rolland the belt transport has been described in FIGS. 5 and 6. Differentembodiments may include alternative transport elements. In accordancewith an embodiment, the runout may include a gripping element, such as,for example, a pair of pliers, which is arranged at the moveable moduleand takes up and holds the good to be removed such that the good ismoved in the direction of the buffer output by the movement of themodule.

The buffers described using FIGS. 2 to 7 allow a filling speed and anemptying speed of the buffer which are principally independent from eachother.

In the embodiments described before, it has been explained that thegoods or groups of goods are arranged in a shingled manner, however, theinvention is not limited to such a kind of buffering. Rather,compartments for taking up goods or groups of goods in a non-shingledmanner may also be provided in the buffer.

An embodiment of an in-feed mechanism in accordance with embodiments ofthe invention will be described below making reference to FIGS. 8 and 9.

FIG. 8 shows a lateral illustration of the in-feed 280. The in-feed 280includes the guiding element 290 which comprises two compartments 300and 302 (see FIG. 9) which extend along the buffer section 204 in thedirection of transport. The compartments 300 and 302 serve for taking upone or several sheets received from a preceding component. Thecompartments 300 and 302 may be controllable such that, when actuatingsame, either both sheets within the arrangement 290 are deposited on thebuffer section 204 and exemplarily, taken up and then clamped by theguiding element 206 a at the, in the direction of transport, back end ofthe sheets. Alternatively, the compartments 300 and 302 may be actuatedsuch that only the group in the bottom compartment 302 is released andthe group 300 in the top compartment is transferred to the bottomcompartment. In FIG. 8, a drive roll for the buffer transport 209 bymeans of which the individual buffer elements 206 are moved in a clockedmanner along the different buffer positions is schematically shown withthe reference numeral 310.

FIG. 9 shows an illustration of an embodiment of the device 290 of FIG.8. The guiding element 290 includes two guiding rails 312 a, 312 b whichare arranged by a distance d transverse to the direction of transport.The guiding rails 312 a and 312 b are implemented each to define thechambers 300 a, 300 b and 302 a, 302 b for receiving the sheets 296 and298, respectively. The guiding rails 312 a and 312 b are rotatable inthe direction of the arrows shown in FIG. 9. In addition, a commontransport element 314 which causes transport of both the bottom sheet296 and the top sheet 298 is provided. As is shown in FIG. 9, a firstpair of chambers 302 a, 302 b is arranged at a bottom positionneighboring to the first buffer position and a second pair of chambers300 a, 300 b is arranged at a top position neighboring to the firstbuffer position.

The mode of functioning of the in-feed described using FIG. 9 will bediscussed in greater detail below. We assume that the sheets areprovided by an arrangement, as is shown using FIG. 1. The merged goodsare taken over together from the merger by the center drive 314 and thetop and bottom sheets are taken over laterally from the merger in theseparate guiding rails such that the sheets are further introduced intothe collection stage. The sheets arrived in the collection stage aredeposited downwards onto the buffer by a rotation by 180° of the lateralguidings 312 a and 312 b. The rotation by an angle of, for example, 180°has the effect that both goods 296, 298 from both pairs of chambers 300a,b, 302 a,b are deposited at the first buffer position. When the grouphas been composed, the buffer is advanced by a corresponding distancepredetermined by the clock such that exemplarily the transport unit 206a arranged at the position 207 a shown in FIG. 8 is advanced by aposition, namely to the position 207 b. Here, the groups may be clampedby the pliers 208 at back left and right sides. The runout releasesclamping so as to let the group continue, exemplarily to the foldingmechanism. Forming groups takes place at the clocking performance of thecutting machine, the runout following in correspondance with the buffer.

With small groups, the buffer is filled quicker than emptied. Inaccordance with embodiments of the invention, the runout travels in thedirection of the folding mechanism, together with the buffer. Withlarger groups, the runout proceeds in the direction of the collectingstage and empties the buffer continuously. An intelligent controllerprovides for the buffer to be filled in correspondence with thecollecting amount. When the buffer reaches its filling limit, the speedof the previous component has, of course, to be reduced.

The runout may pass on groups with a small distance between goods,thereby allowing a folding mechanism, for example, to be used optimally,wherein at the same time the transport speed of the folding mechanismmay be reduced.

With unpaired goods, i.e. when receiving two sheets 296 and 298 whichbelong to different groups to be collected, the lateral guidings arerotated only by 90°. The bottom sheet is placed with its group on thebuffer, the top sheet is given from the top to the bottom guiding rail.A maximum of two sheets are collected in the bottom guiding rail. Whenbeing transported to the buffer, the sheets are deposited by the lateralguidings such that no additional vibration is necessary. Thus, rotationof the guidings by an angle of, for example, 90° causes the good 296contained in the first pair of chambers 302 a, 302 b to be deposited atthe first buffer position and the first pair of chambers 302 a, 302 b tobe moved from the bottom position (exemplarily to the top position). Atthe same time, the second pair of chambers 300 a, 300 b with the good(298) contained therein is moved to the bottom position.

It is pointed out here that more than two pairs of chambers which may bemoved through different positions by a suitable mechanism may also beprovided such that one or several of the chambers are discharged at thefirst buffer position, depending on the movement.

Instead of the in-feed described using FIGS. 8 and 9, otherimplementations of the in-feed may also be used, exemplarily an in-feedmay comprise a transport mechanism for transferring a good or a group ofgoods from a preceding component to the first buffer position by meansof a roll or belt transport, wherein the feeding transport, for example,essentially is in the plane of the buffer section.

FIG. 10 shows a buffer section in accordance with another embodiment ofthe invention. In contrast to the embodiments described so far in whichbelts or roll transports have been used, a vacuum transport is used inthe buffer section in accordance with FIG. 10.

The buffer section 400 shown in FIG. 10 includes an in-feed 402 and arunout 404. The buffer section includes a top transport 406 and a bottomtransport 408 between which a group or group of goods is moved. At thein-feed 402, both the top transport 406 and the bottom transport 408include an in-feed roll 410 a, 410 b between which a good or group ofgoods introduced into the buffer section 400 is conveyed. In addition,the top transport 406 includes a top vacuum transport 412 including abelt 412 a guided over two rolls 412 b and 412 c. Furthermore, the topvacuum transport 412 includes a plurality of vacuum chambers 412 d. Thebottom transport 408 includes a bottom vacuum transport 414 which,similarly to the top vacuum transport 412, comprises a belt 414 a guidedaround two rolls 414 b and 414 c. Additionally, the bottom transportincludes a plurality of vacuum chambers 414 d. The vacuum transports 412and 414 each include selectively controllable vacuum chambers 412 d and414 d, respectively, wherein transport of a good or group of goods maytake place by transporting only at those positions along the belt wherethe associated vacuum chambers are provided with a vacuum. In FIG. 10,the vacuum chambers of the top transport 412 and the bottom transport414 characterized by an “x” are inactive, i.e. despite a movement of thecorresponding belts 412 a and 414 a, no good or group of goods isconveyed at these positions.

In the embodiment shown in FIG. 10, the buffer section 400 includes thebottom and top drives or transports 412 and 414 just described which mayeach be controlled separately from each other. More precisely, therespective drives each include separately controllable vacuum chambers,wherein the number of vacuum chambers is not limited to that shown inFIG. 10, rather more or less vacuum chambers may be provided as long asthere is more than one vacuum chamber in each transport. In accordancewith embodiments, controlling the vacuum chambers is done via amulti-channel valve.

The functionality of the buffer section 400 described using FIG. 10 issuch that the top transport 406 is responsible for accepting a good orgroup of goods from the in-feed 402 and for transporting the good orgroup of goods along the buffer section. The individual goods or groupof goods are introduced into the buffer section 400 at the in-feedspeed. The vacuum chambers 412 d of the top transport are activated upto the good running out, which means that all the goods or groups ofgoods, except for the good running out, are held by the toptransport/drive and transported in the direction of the runout 404 in aparticular transport speed. Thus, a plurality of positions where a goodor a group of goods may be received is defined by the top activatedvacuum chambers 412 d, wherein in the example shown in FIG. 10 therespective positions are defined fixedly or variably. In accordance withthe embodiment of FIG. 10, it may be provided for each of the vacuumchambers 412 d to define a position or buffer position and for thisdefinition to be predetermined fixedly. Alternatively, however, it mayalso be provided for to control two or several vacuum chambers 412 dtogether and thus to set a number of positions along the buffer section400 variably, wherein the same number of vacuum chambers 412 d does notnecessarily have to be united to form one position, but also differentnumbers of vacuum chambers may define a position. In the example shownin FIG. 10, the activated vacuum chambers 412 d of the top transport 412are referred to by 1 to 11. These vacuum chambers are passed when a goodor group of goods is introduced. The last activated vacuum chamber inthe example shown in FIG. 10 is the vacuum chamber referred to by 11.The following vacuum chambers referred to by the “x” are not required,i.e. the buffer is not filled completely. When introducing another goodinto the buffer, the vacuum chamber following vacuum chamber 11 isactivated such that the movement of the belt causes transport of thegoods such that a new good to be taken up is conveyed by the vacuumchamber 1.

The bottom transport 408 is responsible for the good or group of goodsto be output. In order to cause moving out of a group of goods or agood, the vacuum chambers 414 d of the bottom transport necessitated forthis, in this case the five vacuum chambers to the right, are activated.FIG. 10 shows a good running out at 416 which is moved in the directionof the runout 414 by the bottom transport 414. The bottom vacuumtransport 414 runs at higher a speed than the buffer transport, whereinthis speed may equal that of the runout transport.

The top and bottom vacuum chambers 412 d and 414 d are controlledsynchronously in correspondence with the position and length of the goodrunning out. The arrow 418 in FIG. 10 shows the borderline of the activeand inactive vacuum chambers 412 d, which follows the position of thegood to be output. As has already been mentioned above, the buffer isfilled quicker with smaller groups than with larger groups such that,when taking up smaller groups, the last occupied buffer position travelsin the direction of the runout 404, whereas with larger groups the lastoccupied position travels in the direction of the in-feed 402, as isindicated by the arrow 418. The vacuum chambers 412 d areactivated/deactivated correspondingly.

An embodiment in which the transports 412 and 414 are arranged one abovethe other is shown in FIG. 10, however, the present invention is notlimited to this. In accordance with other embodiments of the invention,the transports 412 and 414 are arranged in the same level, thefunctionality described above remaining the same.

Although some aspects have been described in connection with a device,it is to be understood that these aspects also represent a descriptionof a corresponding method such that a block or element of a device isalso to be interpreted to be a corresponding method step orcharacteristic of a method step. In analogy, aspects having beendescribed in connection with a method step or as a method step, alsorepresent a description of a corresponding block or detail orcharacteristic of a corresponding device.

While this invention has been described in terms of several embodiments,there are alterations, permutations, and equivalents which will beapparent to others skilled in the art and which fall within the scope ofthis invention. It should also be noted that there are many alternativeways of implementing the methods and compositions of the presentinvention. It is therefore intended that the following appended claimsbe interpreted as including all such alterations, permutations, andequivalents as fall within the true spirit and scope of the presentinvention.

1. A device for buffering a plurality of individual sheets or groups ofsheets, comprising: a buffer section configured to receive a pluralityof individual sheets or groups of sheets; a buffer transport configuredto move an individual sheet or group of sheets at a buffer transportspeed; and a runout configured to move out an individual sheet or groupof sheets from the device at a runout speed which is higher than thebuffer transport speed; wherein the runout is configured to act on anindividual sheet or group of sheets at a last occupied position alongthe buffer section so as to take over transport of the individual sheetor the group of sheets before the individual sheet or group of sheetshas reached an end of the buffer section.
 2. The device in accordancewith claim 1, comprising a sensor circuit configured to detect aposition of an individual sheet or group of sheets along the buffersection.
 3. The device in accordance with claim 2, wherein the buffersection comprises a plurality of successive buffer positions, eachbuffer position being configured to receive an individual sheet or groupof sheets, and wherein the sensor circuit comprises a plurality ofsensors, at least one sensor each being associated to a buffer positionso as to determine whether the buffer position is occupied orunoccupied, wherein the runout is configured to determine, based on thesensor signals, the buffer position along the buffer section where therunout takes over transport of an individual sheet or group of sheets.4. The device in accordance with claim 1, wherein the buffer transportcomprises pliers transport or stud transport, wherein the pliers orstuds of the buffer transport comprise fixed distances to one another incorrespondence with the distance of buffer positions along the buffersection.
 5. The device in accordance with claim 1, wherein the buffertransport and the runout each comprise different transport elements. 6.The device in accordance with claim 5, wherein the buffer transportcomprises a pliers transport or stud transport, and wherein the runoutcomprises a roll or belt transport.
 7. The device in accordance withclaim 1, wherein the buffer section comprises a plurality of successivebuffer positions, each buffer position being configured to receive anindividual sheet or group of sheets, and wherein the runout comprises aplurality of runout modules, a runout module each being associated to aplurality of buffer positions starting from a last buffer position alongthe buffer section, each module being actuatable selectively forengaging a buffered individual sheet/buffered group of sheets at abuffer position, and the runout modules between an output of the deviceand the last occupied buffer position along the buffer section beingactuated so as to move out an individual sheet or group of sheets fromthis device.
 8. The device in accordance with claim 7, wherein each ofthe plurality of runout modules comprises a conveyer element, theconveyer element being arranged to be displaced between a first positionand a second position, the conveyer element in the first position notengaging an individual sheet or group of sheets, and the conveyerelement in the second position engaging an individual sheet or group ofsheets.
 9. The device in accordance with claim 7, wherein each of theplurality of runout modules comprises a conveyer element arranged at afixed position, the conveyer element being implemented to be rotatedbetween a first position and a second position when being actuated, theconveyer element in the first position not engaging an individual sheetor group of sheets, and the conveyer element in the second positionengaging an individual sheet or group of sheets.
 10. The device inaccordance with claim 1, wherein the buffer section comprises aplurality of successive buffer positions, each buffer position beingconfigured to receive an individual sheet or group of sheets, andwherein the runout comprises a moveable runout module configured to bemoved to the last occupied buffer position along the buffer section fortaking over transport of the sheet or group of sheets comprised therein.11. The device in accordance with claim 10, comprising: a belt transportcomprising a belt extending from an inlet of the buffer section to anoutlet of the buffer section, wherein the moveable runout modulecomprises: a conveyer element moveable between a first position and asecond position, the conveyer element in the first position not engagingan individual sheet or group of sheets, and the conveyer element in thesecond position engaging an individual sheet or group of sheets; and apair of rolls receiving the belt of the belt transport such that thebelt does not engage the individual sheet or group of sheets in front ofthe moveable runout module in the direction of transport of theindividual sheet or group of sheets and engages an individual sheet orgroup of sheets after the moveable runout module in the direction oftransport, wherein the conveyer element is operative to engage anindividual sheet or group of sheets using the belt of the belttransport.
 12. The device in accordance with claim 11, wherein theconveyer element is arranged for being shifted or rotated between thefirst position and the second position.
 13. The device in accordancewith claim 8, wherein the conveyer element comprises a roll, two or morerolls arranged one behind the other in the direction of transport of theindividual sheet or group of sheets, a belt or a roll comprising aD-shaped cross-section.
 14. The device in accordance with claim 1,comprising: an in-feed configured to feed an individual sheet or groupof sheets to the buffer section, wherein the in-feed comprises a drivefor transporting an individual sheet or group of sheets, and a pair oflateral guidings, wherein each of the lateral guidings comprises atleast two chambers which define pairs of chambers for receiving each atleast one sheet, a first pair of chambers being arranged at a bottomposition neighboring to the buffer section, and a second pair ofchambers being arranged at a top position spaced apart from the buffersection, wherein the guidings are arranged rotatably and arecontrollable so as to cause rotation by a first angle or by a secondangle, wherein the rotation by the first angle causes both goods fromboth pairs of chambers to be fed to the buffer section, and wherein arotation by the second angle causes the sheet comprised in the firstpair of chambers to be fed to the buffer section and the first pair ofchambers to be moved from the bottom position, and the second pair ofchambers, with the sheet comprised therein, to be moved to the bottomposition.
 15. The device in accordance with claim 1, wherein: the buffertransport comprises a first vacuum transport comprising a plurality ofselectively activatable vacuum chambers, and the runout comprises asecond vacuum transport comprising a plurality of selectivelyactivatable vacuum chambers.
 16. The device in accordance with claim 15,wherein receiving of the individual sheet or group of sheets is causedby one or several of the activated vacuum chambers of the first vacuumtransport.
 17. The device in accordance with claim 15, wherein the firstand second vacuum transports are arranged next to each other or aboveeach other.
 18. The device in accordance with claim 1, wherein thebuffer section is configured to receive the sheets or group of sheets ina shingled or non-shingled manner.
 19. A paper handling systemcomprising: one or several handling stages; and at least one device forbuffering a plurality of individual sheets or groups of sheets,comprising: a buffer section configured to receive a plurality ofindividual sheets or groups of sheets; a buffer transport configured tomove an individual sheet or group of sheets at a buffer transport speed;and a runout configured to move out an individual sheet or group ofsheets from the device at a runout speed which is higher than the buffertransport speed; wherein the runout is configured to act on anindividual sheet or group of sheets at a last occupied position alongthe buffer section so as to take over transport of the individual sheetor the group of sheets before the individual sheet or group of sheetshas reached an end of the buffer section for collecting individualsheets or groups of sheets.
 20. The paper handling system in accordancewith claim 19, wherein the handling stages comprise a cutter, a mergerand a folding mechanism, wherein the device for collecting theindividual sheets or groups of sheets is arranged between the merger andthe folding mechanism.
 21. A method for buffering a plurality ofindividual sheet or groups of sheets in a buffer section for receiving aplurality of individual sheet or groups of sheets, a buffer transportmoving an individual sheet or group of sheets at a buffer transportspeed, and a runout moving out an individual sheet or group of sheets ata runout speed which is higher than the buffer transport speed;comprising: acting, by the runout for moving out, on an individual sheetor group of sheets at a last occupied position along the buffer sectionso as to take over transport of the individual sheet or the group ofsheets before the individual sheet or group of sheets has reached an endof the buffer section.